1. Field of the Invention
The present invention relates to an automotive weather strip produced by forming a urethane layer on the surface of a base material containing an ethylene/propylene rubber. The automotive weather strip is a rubber article which is fixed to the window of automobiles in order to closely contact the movable window glass with the window frame through it, thereby preventing rain water and open air from entering automobiles. This weather strip is also called a draining rubber, glass-run-channel, door glass and the like.
2. Description of the Related Art
In the automotive industry, ethylene/propylene rubber is used over a wide range as a weather strip, etc. because of its excellent weather resistance, heat resistance and ozone resistance. However, when this rubber is used in automotive weather strip, a large friction coefficient between the rubber and the glass prevents smooth sliding of the window. In order to improve the sliding property, there is used a method of applying urethane of small friction coefficient to the surface of the ethylene/propylene rubber that is a base material. However, a sufficient adhesion strength between the rubber and the urethane layer cannot be obtained by merely applying urethane to the rubber. Therefore, in order to improve the adhesion between the ethylene/propylene rubber and the urethane layer, a method has conventionally been used in which the rubber is buffed and coated with a primer obtained by dissolving an adhesive in a solvent, and then urethane is applied to the primer layer. This conventional method is, however, disadvantageous in terms of economy because it requires many production steps as described above. It also has another problem that solvent-containing primers are not good for the working environment.
In view of this situation, an object of the present invention is to provide a novel automotive weather strip in which the base material containing an ethylene/propylene rubber has been strongly adhered to a urethane layer forming a surface layer, and which can be produced efficiently without requiring numerous production steps and also without using a hygienically undesirable solvent-containing adhesive.
Another object of the present invention is to provide an adhesive composition for use between ethylene/propylene rubbers and urethanes.